refactor: better logger

CMakeLists.txt

@@ -28,7 +28,7 @@ if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
         ${PROJECT_SOURCES}
         src/images_carousel.h src/images_carousel.cpp src/designer/images_carousel.ui
         src/config.h src/config.cpp
-        src/logger.h
+        src/logger.h src/logger.cpp
         src/loading_indicator.h src/loading_indicator.cpp src/designer/loading_indicator.ui
     )
     # Define target properties for Android with Qt 6 as:

src/images_carousel.cpp

@@ -1,7 +1,7 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 01:22:53
- * @LastEditTime: 2025-08-07 00:50:11
+ * @LastEditTime: 2025-08-07 02:01:23
  * @Description: Animated carousel widget for displaying and selecting images.
  */
 #include "images_carousel.h"
@@ -172,6 +172,7 @@ void ImageLoader::run() {
 ImageData::ImageData(const QString& p, const int initWidth, const int initHeight) : file(p) {
     if (!image.load(p)) {
         warn(QString("Failed to load image from path: %1").arg(p));
+        return;
     }
     // resize in "cover" mode
     const QSize targetSize(initWidth, initHeight);
@@ -290,7 +291,12 @@ ImageItem::ImageItem(const ImageData* data,
       m_itemSize(itemWidth, itemHeight),
       m_itemFocusSize(itemFocusWidth, itemFocusHeight) {
     setScaledContents(true);
-    setPixmap(QPixmap::fromImage(data->image));
+    if (data->image.isNull()) {
+        setText(":(");
+        setAlignment(Qt::AlignCenter);
+    } else {
+        setPixmap(QPixmap::fromImage(data->image));
+    }
     setFixedSize(itemWidth, itemHeight);
 }
 

src/logger.cpp

@@ -0,0 +1,106 @@
+/*
+ * @Author: Uyanide pywang0608@foxmail.com
+ * @Date: 2025-08-07 01:12:37
+ * @LastEditTime: 2025-08-07 01:55:56
+ * @Description: Implementation of logger.
+ */
+#include "logger.h"
+
+#include <unistd.h>
+
+#include <QObject>
+#include <QProcessEnvironment>
+#include <QString>
+#include <QTextStream>
+#include <QThreadPool>
+
+#ifdef GENERAL_LOGGER_DISABLED
+#define ENSURE_ENABLED return;
+#else
+#define ENSURE_ENABLED
+static QTextStream s_logStream(stderr);
+#endif
+
+Logger* Logger::instance(FILE* stream) {
+    static Logger* logger{};
+    if (!logger) {
+        if (!stream) {
+            stream = stderr;  // Default to stderr if no stream provided
+        }
+        logger = new Logger(stream);
+    }
+    return logger;
+}
+
+Logger::Logger(FILE* stream, QObject* parent)
+    : QObject(parent), m_stream(stream), m_logStream(stream) {
+    connect(this,
+            &Logger::logSig,
+            this,
+            &Logger::_log,
+            Qt::QueuedConnection);
+}
+
+void Logger::_log(
+    const QString& msg,
+    const QString& levelString,
+    const QString& levelColorString,
+    const QString& textColorString,
+    const GeneralLogger::LogIndent indent) {
+    ENSURE_ENABLED
+
+    s_logStream << levelColorString << levelString << ' ';
+    for (qint32 i = 0; i < indent; i++) s_logStream << "  ";
+    s_logStream << textColorString << msg << (textColorString.isEmpty() ? "\n" : "\033[0m\n");
+    s_logStream.flush();
+}
+
+bool Logger::isColored() {
+    const auto stream = Logger::instance()->m_stream;
+    if (!isatty(fileno(stream))) {
+        return false;
+    }
+    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+    QString term            = env.value("TERM");
+    if (term.isEmpty() || term == "dumb") {
+        return false;
+    }
+    return true;
+}
+
+void GeneralLogger::info(
+    const QString& msg,
+    const GeneralLogger::LogIndent indent) {
+    ENSURE_ENABLED
+    constexpr const char* colorInfoMsg[]{"\033[32m", "\033[0m", "\033[0m"};
+    const auto color = Logger::isColored();
+    emit Logger::instance() -> logSig(msg,
+                                      "[INFO]",
+                                      color ? "\033[92m" : "",
+                                      color ? colorInfoMsg[indent] : "",
+                                      indent);
+}
+
+void GeneralLogger::warn(
+    const QString& msg,
+    const GeneralLogger::LogIndent indent) {
+    ENSURE_ENABLED
+    const auto color = Logger::isColored();
+    emit Logger::instance() -> logSig(msg,
+                                      "[WARN]",
+                                      color ? "\033[93m" : "",
+                                      color ? "\033[33m" : "",
+                                      indent);
+}
+
+void GeneralLogger::error(
+    const QString& msg,
+    const GeneralLogger::LogIndent indent) {
+    ENSURE_ENABLED
+    const auto color = Logger::isColored();
+    emit Logger::instance() -> logSig(msg,
+                                      "[ERROR]",
+                                      color ? "\033[91m" : "",
+                                      color ? "\033[31m" : "",
+                                      indent);
+}

src/logger.h

@@ -1,71 +1,62 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 10:43:31
- * @LastEditTime: 2025-08-05 17:25:18
+ * @LastEditTime: 2025-08-07 01:55:42
- * @Description: A simple logger for general use.
+ * @Description: A simple thread-safe logger for general use.
- *               g_logStream must be defined somewhere else in the project.
  */
 #ifndef GENERAL_LOGGER_H
 #define GENERAL_LOGGER_H
 
+#include <QObject>
 #include <QString>
 #include <QTextStream>
 
 namespace GeneralLogger {
 
-inline constexpr const char* colorInfoMsg[]{"\033[32m", "\033[0m", "\033[0m"};
-
 enum LogIndent : qint32 {
     GENERAL = 0,
     STEP    = 1,
     DETAIL  = 2,
 };
 
-#ifdef GENERAL_LOGGER_DISABLED
+void info(const QString& msg,
-#define ENSURE_ENABLED return;
+          const LogIndent indent = GENERAL);
-#else
-#define ENSURE_ENABLED
-extern QTextStream g_logStream;
-#endif
 
-inline void
+void warn(const QString& msg,
-info(const QString& msg,
+          const LogIndent indent = GENERAL);
-     const LogIndent indent = GENERAL,
-     const bool color       = true) {
-    ENSURE_ENABLED
 
-    g_logStream << (color ? "\033[92m" : "") << "[INFO] ";
+void error(const QString& msg,
-    for (qint32 i = 0; i < indent; i++) g_logStream << "  ";
+           const LogIndent indent = GENERAL);
-    g_logStream << (color ? colorInfoMsg[indent] : "") << msg << (color ? "\033[0m\n" : "\n");
+}  // namespace GeneralLogger
-    g_logStream.flush();
-}
 
-inline void
+class Logger : public QObject {
-warn(const QString& msg,
+    Q_OBJECT
-     const LogIndent indent = GENERAL,
-     const bool color       = true) {
-    ENSURE_ENABLED
 
-    g_logStream << (color ? "\033[93m" : "") << "[WARN] ";
+  public:
-    for (uint32_t i = 0; i < indent; i++) g_logStream << "  ";
+    static Logger* instance(FILE* stream = nullptr);
-    g_logStream << (color ? "\033[33m" : "") << msg << (color ? "\033[0m\n" : "\n");
-    g_logStream.flush();
-}
 
-inline void
+    static bool isColored();
-error(const QString& msg,
-      const LogIndent indent = GENERAL,
-      const bool color       = true) {
-    ENSURE_ENABLED
 
-    g_logStream << (color ? "\033[91m" : "") << "[ERROR] ";
+  private:
-    for (uint32_t i = 0; i < indent; i++) g_logStream << "  ";
+    explicit Logger(FILE* stream, QObject* parent = nullptr);
-    g_logStream << (color ? "\033[31m" : "") << msg << (color ? "\033[0m\n" : "\n");
-    g_logStream.flush();
-}
 
-#undef ENSURE_ENABLED
+  private slots:
+    void _log(const QString& msg,
+              const QString& levelString,
+              const QString& levelColorString,
+              const QString& textColorString,
+              const GeneralLogger::LogIndent indent);
 
-};  // namespace GeneralLogger
+  private:
+    FILE* m_stream;
+    QTextStream m_logStream;
+
+  signals:
+    void logSig(const QString& msg,
+                const QString& levelString,
+                const QString& levelColorString,
+                const QString& textColorString,
+                const GeneralLogger::LogIndent indent);
+};
 
 #endif  // GENERAL_LOGGER_H

src/main.cpp

@@ -1,7 +1,7 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 00:37:58
- * @LastEditTime: 2025-08-05 19:42:07
+ * @LastEditTime: 2025-08-07 01:49:07
  * @Description: Entry point.
  */
 #include <qapplication.h>
@@ -12,11 +12,8 @@
 #include <QTextStream>
 
 #include "config.h"
-#include "logger.h"
 #include "main_window.h"
 
-QTextStream GeneralLogger::g_logStream(stderr);
-
 static QString getConfigDir() {
     auto configDir = QStandardPaths::writableLocation(QStandardPaths::AppConfigLocation);
     if (configDir.isEmpty()) {